You spent real money on a Shun or a Miyabi, and now there are tiny nicks along the edge. It feels like you broke it.
Why is my Japanese knife chipping?
TL;DR: Japanese knives use harder, thinner steel than Western ones. That gives you a keener edge, but it also makes the edge brittle. Most chips come from sideways force: twisting through dense food, scraping the board, or a knock in the drawer. It usually isn’t a defect, and it usually isn’t your knife skills.
The good news is that chipping is predictable. Once you understand the steel, you can stop it.
Hard steel cuts beautifully and chips easily
Steel hardness is measured on the Rockwell C scale, written as HRC. A higher number means harder steel.
Western knives like Wüsthof and Zwilling sit lower on that scale, often around 56 to 58 HRC. They use a tougher, slightly softer steel, so when they meet stress, the edge tends to roll over rather than break (Cook’s Illustrated).
Japanese knives go the other way. Many run 60 HRC and up, and premium powdered steels like SG2 reach into the 64 to 66 range. That hardness is what lets them take and hold such a fine edge. The trade-off is brittleness: harder steel is more prone to chipping if it gets handled roughly (Misen). It is a genuine paradox of the craft. The same property that makes the knife so sharp is what makes the edge fragile.
The edge is thinner than you think
Hardness is only half of it. The other half is geometry.
A Western chef’s knife is usually ground to roughly 20 degrees per side. Shun grinds most of its double-bevelled knives to about 16 degrees per side (Shun). That sounds like a small difference. It isn’t. A thinner angle means less metal sitting behind the very tip of the edge, so there is less steel to support it when something pushes sideways.
Put the two together. You have hard, brittle steel formed into a thin, acute edge. It slices cleanly through a tomato with almost no pressure. It also has very little tolerance for force coming from the wrong direction.
So what actually causes the chips?
Almost always, lateral stress. The edge is built to move straight down and forward through food. It is not built to twist or pry.
The usual culprits:
- Twisting the blade through something dense like a butternut squash or a hard cheese. A small twist plus a thin, hard edge equals a chip (ChefPanko).
- Scraping food off the board with the sharp edge. Use the spine instead.
- Hard targets: bones, frozen food, fruit pits, chocolate. The knife will lose that fight.
- The wrong board. Glass, stone, and ceramic are harder than your edge. Stick to end-grain wood or soft poly.
- The dishwasher and the drawer. Loose knives knocking against other steel chip in storage, not just in use.
None of these are about skill. They are about asking a precision tool to do a rough job.
Can a chipped knife be saved?
Usually, yes. Sharpening removes a small amount of metal and brings the bevels back to a clean point past the damage. A few microchips disappear in a normal sharpening. A deeper chip takes more: the edge has to be ground back until it reaches solid steel, then re-profiled to the right angle along the whole length.
This is where the sharpener matters more than usual. A hard, thin Japanese edge is exactly the kind of blade a careless grinder ruins, by overheating the steel or by sharpening a 16-degree asymmetric edge as if it were a 20-degree German one. The fix should respect the geometry the maker intended.
The bottom line
Your knife is chipping because it is doing its job at the edge of what hard steel can take. Cut down, not sideways. Keep it off bone, frozen food, and glass boards. Wash it by hand, and store it in a block, on a strip, or in a guard so it never knocks into other metal.
When it does chip, and most do eventually, get it sharpened by someone who works on Japanese steel by hand and water-cooled, not on a dry high-speed wheel. At Slicey we sharpen Shun, Miyabi, and Konosuke to the angle they were made for, here in Midtown Toronto. A good chip is a quick fix. A blade ruined by the wrong sharpener often isn’t.